42 ABORIGINAL MONUMENTS
a point which remains to be settled by more extended observations.*
There is another description of mounds which should properly be here mentioned. Their purposes admit of no doubt. They consist of pyramidal structures, or “elevated squares,” and are found almost invariably within enclosures.
Fic. 4.
They are sometimes of large dimensions. Those at Ma- rietta are fair examples of the class, and No. 1, Fig. 4, exhibits their structure and dimensions. Wo. 2, is an ele-
= Upon many prominent and commanding points of the hills, are to be observed traces of large and long-continued fires, These are yulgarly sup- posed to be the remains of “furnaces,” from the amount of scoriaceous mate- rial scattered upon the surface. The fires appear to have been built upow heaps of stones, which are broken up, and sometimes partially vitrified, and in all cases exhibit the marks of intense and protracted heat.
Lighting fires as signals, upon elevated positions, is an old and almost universal practice. When Lieut. Fremont penetrated into the fastnesses of Upper California, where his appearance created great alarm among the In- dians, he observed this primitive telegraph system im operation. “Columns of smoke rose over the country at scattered intervals—signals by which the In- dians here, as elsewhere, communicate to each other that enemies are in the country. It isa signal of ancient and very universal application among barba- rians.’—Fremont’s Second Expedition, p. 220.
